11.5' Triangle Outdoor Sun Sail Shade Shading Blue Effective harmful UV blocking. Air circulation possible - Specially knitted high-density polyethylene fabric. Environmental temperature below the shading sail can be lowered up 6.5 degrees centigrade! Applicable for all season - Mildew and mold free. Rust-proof fixing system - Galvanized iron tension rings. Easy installation- With mounted tension rings at the tip of corner, can be easily fixed onto or detached from existing structures.